Readily soluble and stable salts of di-



United States Paten READILY'S OLUBLE AND STABLE SALTS OF DL 1 (4-AMlDINO-PHENYL) TRIAZENE (N-L3) AND A PROCESS OF PREPARING THEM Richard Brodersen, Frankfurt am Main, Heinz Loewe, Kelkheim, Taunus, and Heinrich Ott, Eppstein, Taunus, Germany, assignors to Farbwerke Hoechst Aktiengesellshaft vormals Meister Lucius & Bruning, Frankfurt am Main, Germany, a corporation of Germany No Drawing. Application March 12, 1956 Serial N--57.0,669

Claims priority, application Germany March 19, 1955 8 Claims. (Cl. 260-'140) The present invention relates to readily soluble and stable salts of the di-(4-amidino-phenyl)-triazene-(N-1L3) and to a process of preparing them.

In U. S. Patent No. 2,673,197 is described a process for preparing the di-(4-amidino-phenyl) triazene (N 1.3) which corresponds to the formula and is known to be a medicament having an excellent action on blood parasites. It is, however, difiicult to prepare from this compound aqueous solutions, since the salts hitherto known are not sufficiently soluble in water and are, therefore, not suitable for use in therapeutics.

Now we have found that readily soluble and at the same time sufliciently stable salts of the di-(4-a midino-phenyl)- triazene-(N-LS) can be prepared by reacting di-(4- amidino-phenyl)-triazene-(N-l.3) in the form of a solution or a suspension with an acylated amino acid corresponding to the formula wherein R represents an aliphatic acyl radical containing at most 4 carbon atoms and X represents an alkylene group. V,

As acylated amino acids suitable for use in the process of this invention there come into consideration especially compounds which correspond to the aforementioned for .mula wherein X stands for an alkylene group containing .1 to 5 carbon atoms. As acids of this kind there may be mentioned more especially: aceturic acid, S-acetylaminopropionic acid, omega-acetylamino-capronic acid, propionyl glycine and butyryl glycine. The novel salts of the present invention have the following structural formula:

wherein R and X have the meanings indicated hereinabove. '7 The process according to this invention mayjbekcon- 2,838,485 Patented June 10, 1958 ICC The process of this invention may also be performed follows:

A suspension of di-(4-amidino-pheny1)-triazene- (N-l.3) in water or an organic solvent is combined with an aqueous solution of the acylated amino acid. From the solution so obtained the salt can be precipitatediby crystallization, for example by cooling or adding a solventin which'the salt formedis insoluble or for example by adding acetone until turbidity occurs.

It is also possible to mix a suspension of di-(4-amidinophenyl)-triazene-(N-l.3) in an organic solvent with the acylated amino acid and to precipitate the salt from the solution obtained by adding, for example, ethyl acetate.

Finally it is possible to combine a solution of the acylated amino acid in an organic solvent with a suspension of di-(4-amidino-phenyl)-triazene-(N-1.3) in water and to separate the salt from the clear solution obtained by adding, for example, isopropanol.

The formation of the salt may be accelerated by stirring or shaking or carefully heating the mixture that contains the components.

The salts of the di-(4-amidino-phenyl)-triazene-(N-1.3) obtained according to this invention exhibit approximately the same tolerability and a corresponding efliciencyagainst blood parasites, and are more readily soluble'inwaterand more stable than the salts already known.

The following examples serve to illustrate the invention, but they are not intended to limit it hereto:

Example 1 23.4 grams of aceturic acid are dissolved in 450 cc. of hot methanol and the solution obtained is stirred with 28.1 grams of di-(4-amidino-phenyl) triazene-(N-1.3). The end solution obtained is' diluted attie- C." with water until completely dissolved and then allowed to stand for 1 day at about 0 C. 37 grams of the salt of diaceturic acid are separated in the form of crystals which melt at 202 C. with decomposition.

100 parts of water dissolve at 20 C. 10 parts of the salt so obtained. I l I i a v Example 2 I 28.1- grams of di-(4-amidino-phenyl)-triazene-(N 1.3) are: suspended in 300 cc. of hot methanol and cc.of an aqueous solution of 35 percent strength of fi acetylaminop'ropionic'acid are then added'to'the suspension obtained. To the mixture that has become clear acetone is added until turbidity occurs, and it is then stored in a refrigerator for crystallization. 40.5 grams of the saltof di-fi-acetylamino-propionic acid are obtained; it melts at 220C3 with decomposition.

parts of water dissolve at 20 C. 20 parts of the salt so obtained.

' Example 3 20 grams of omega-acetylamino-capronic acid are added to a suspension 14 grams of di-(4-amidino-phenyl)- triazene-(N-LB) in 250 cc. of ethyl alcohol, the solution obtained is filtered until clear and the salt is precipitated with 250 cc. of ethyl acetate. The salt of di-omega-acetylamino-capronic acid is obtained in a yield of 25 grams. The salt melts at 200" C. with decomposition.

100 parts of water dissolve at 20 C. 25 parts of the salt so obtained.

Example 4 7.86 grams of propionyl glycine are dissolved in 50 cc.

. a 3' of methanol and the solution so obtained is added to a suspension of8.43 grams of di-(4-amidino-phenyl)-triazene- (N-1.3) in 40 cc. of water. By addingisopropanol to the clear solution so obtained 11 grams of the salt of di-pro- 4 wherein R represents an aliphatic acyl radical containing at most 4 carbon atoms and X represents an alkylene group with at most 5 carbon atoms.

2. The compound of the formula pionyl amino acetic acid are separated; itrneltsat 217 C. with decomposition. i

3. The compound of the formula 4. The compound of the formula .5. The compound of the formula 100 parts1ofvvater. dissolve at20 C. 2 to 31parts of the salt so obtained;

6. The compound of the formula Example 5 2.90 of butyryl glycine are dissolved in 15 cc. of

7. The process for preparing readily soluble andstable salts of'the general formula 45 wherein R represents an aliphatic acyl radical containing at most 4 carbon atoms andX represents an alkylene group vvith at most 5 carbon atoms, which comprises contacting in an inert'liquid medium di-(4-arnidino-phenyl) triazene-(N-L3) with an acylated amino acid corresponding to the formula v R--NH -X-COOH wherein R and X have the meanings given above.

8. The. process as claimed in claim 7, wherein the acylated amino acid is aceturic acid.

References Cited in the file of this patent UNITED STATES PATENTS 2,256,759 Ham 2,279,514 Ham et al. 2,673,197 Jensch Sept. 23, 1941 Apr. 14, 1942 Mar. 23, 1954 OTHER REFERENCES vol. 24, page 2990 (1930). 

1. READILY SOLUBLE AND STABLE SALTS OF THE GENERAL FORMULA 